The present invention relates to a driving assembly for moving a slidable member of a slide gate on a metallurgical vessel, the assembly being of the type including a thrust rod of the slide that is to be moved in opposite directions, a drive unit that is movable, for example in directions different from that of movement of the thrust rod, and at least one deflection member to be pivoted to the vessel and connecting the drive unit to the thrust rod to transfer or transduce movement of the drive unit to movement of the thrust rod.
A driving assembly of this general type is disclosed in EP-A1 0 047 538 and is operable to open and close a slide gate. A drive unit is mounted on the side of a metallurgical vessel and is manually operable. Movement of the drive unit generally vertically is transduced or transferred by way of a simple lever system into generally horizontal movement of a thrust rod of a slide of the slide gate. The lever system includes a toggle lever that is pivoted at approximately a center thereof to the metallurgical vessel. One end of the toggle lever is hinged to a vertical rod that is part of or driven by the drive unit, and the other end of the toggle lever is hinged to a horizontal rod that is part of or connected to the thrust rod of the slide of the slide gate. The toggle lever thus is rotated about its pivot axis, with the result that the thrust rod and the slide are moved back and forth in opposite directions. The connecting point of the toggle lever with the thrust rod is caused to be moved along a circular arc. The thrust rod however must be moved only rectilinearly. Therefore, a connecting rod or lever is connected between the toggle lever and the thrust rod. However, one disadvantage of this lever system is the generation of relatively large transverse or cross forces that act from the toggle lever on the thrust rod. On the one hand, the existence of such forces requires that the thrust rod be mounted in a relatively massive bearing. On the other hand, practical operations and installations repeatedly have demonstrated that, despite such relatively massive bearings, such forces can lead to jamming of the thrust rod or to heavy wear of such bearings. Furthermore, in the case of large slide gates, it is necessary to employ powered drive units, for example hydraulic piston-cylinder units. When using such units, the transverse or cross forces that are generated are significantly larger. As a result, the application of such larger forces to the thrust rod of the slide cause jamming or wear of the bearing to occur even sooner.